need a combo surface temp sensor / switch

I'm trying to control surface temperature and keep it between 200 and
500 degrees F. I'll need a device that will monitor surface temperatue
and complete one circuit if the temperature goes below 200 degrees F.
and complete a different cicuit if the temperature exceeds 500 degrees
F.

If I had to go with two separate devices, one for the lower limit and
another for the upper limit, that would be fine too.

Could anyone point me in the right direction? My electronics expetise
is pretty limited, but I'm willing to do what I've got to do in order
to get this done. Thank you in advance for your time on this matter.

T1G